Rudbeckia hirta

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Rudbeckia hirta
Black eyed susan 20040717 110754 2.1474.jpg
Rudbeckia hirta flowerhead
Scientific classification
R. hirta
Binomial name
Rudbeckia hirta

Black-eyed Susan

Rudbeckia hirta, commonly called black-eyed Susan, is a North American flowering plant in the sunflower family, native to Eastern and Central North America and naturalized in the Western part of the continent as well as in China. It has now been found in all 10 Canadian Provinces and all 48 of the states in the contiguous United States.[2][3][4]

Rudbeckia hirta is one of a number of plants with the common name black-eyed Susan. Other common names for this plant include: brown-eyed Susan, brown betty, gloriosa daisy, golden Jerusalem,[5][6] English bull's eye, poor-land daisy, yellow daisy, and yellow ox-eye daisy.[7]

Rudbeckia hirta is the state flower of Maryland.[8]

The plant also is a traditional Native American medicinal herb in several tribal nations;[9] believed in those cultures to be a remedy, among other things, for colds, flu, infection, swelling and (topically, by poultice) for snake bite (although not all parts of the plant are edible)[9]

Parts[which?] of the plant have nutritional value. Other parts are not edible.


Rudbeckia hirta is an upright annual (sometimes biennial or perennial) growing 30–100 cm (12–39 in) tall by 30–45 cm (12–18 in) wide. It has alternate, mostly basal leaves 10–18 cm long, covered by coarse hair, with stout branching stems and daisy-like, composite flower heads appearing in late summer and early autumn. In the species, the flowers are up to 10 cm (4 in) in diameter, with yellow ray florets circling conspicuous brown or black, dome-shaped cone of many small disc florets.[10] However, extensive breeding has produced a range of sizes and colours, including oranges, reds and browns.[3][11]


The specific epithet hirta is Latin for “hairy”, and refers to the trichomes (hairs) occurring on leaves and stems.[12]


There are four varieties[1][3]


Rudbeckia hirta is widely cultivated in parks and gardens, for summer bedding schemes, borders, containers, wildflower gardens, prairie-style plantings and cut flowers. Numerous cultivars have been developed, of which 'Indian Summer'[13] and 'Toto'[14] have gained the Royal Horticultural Society's Award of Garden Merit.[15] Other popular cultivars include 'Double Gold' and 'Marmalade'.

Gloriosa daisies are tetraploid cultivars having much larger flower heads than the wild species, often doubled or with contrasting markings on the ray florets. They were first bred by Alfred Blakeslee of Smith College by applying colchicine to R. hirta seeds; Blakeslee's stock was further developed by W. Atlee Burpee and introduced to commerce at the 1957 Philadelphia Flower Show.[16] Gloriosa daisies are generally treated as annuals or short-lived perennials and are typically grown from seed, though there are some named cultivars.

Symbolism and uses[edit]

Maryland state flower[edit]

  • The black-eyed Susan was designated the state flower of Maryland in 1918.[8][17] In this capacity it is used in gardens and ceremonies to celebrate, memorialize and show affection for the state of Maryland and its people.
  • The Preakness Stakes in Baltimore, Maryland, has been termed "The Run for the Black-Eyed Susans" because a blanket of Viking Poms, a variety of chrysanthemums resembling black-eyed Susans, is traditionally placed around the winning horse's neck (actual black-eyed Susans are not in bloom in May during the Preakness).[18]

University of Southern Mississippi[edit]

In 1912, the black-eyed Susan became the inspiration for the University of Southern Mississippi school colors (black and gold), suggested by Florence Burrow Pope, a member of the university's first graduating class. According to Pope: “On a trip home, I saw great masses of Black-Eyed Susans in the pine forests. I decided to encourage my senior class to gather Black-Eyed Susans to spell out the name of the class on sheets to be displayed during exercises on Class Day. I then suggested black and gold as class colors, and my suggestion was adopted."[19]

Butterfly attractant for enhancing gardens[edit]

It is a larval host to the bordered patch, gorgone checkerspot, and silvery checkerspot species[21].

Traditional Native American medicinal uses[edit]

Juice from the roots has been used as drops for earaches.[9]

Nutritional parts[edit]

  • Certain parts of the plant contains anthocyanins[23] a class of antioxidant with purported health benefits.


  • As with any wild plant, it is usually recommended to research carefully before consuming as not all parts of the plant may be edible and to avoid mis-identification with other plants that may look similar to the black eyed Susan.
  • It is widely recommended always to consult one's doctor before taking any medicinal herb.
  • With any herb approved by a doctor for use, it is widely agreed that recommended dosages and preparation procedures should always be followed.
  • The species is also known to be toxic to cats when ingested.[24]



  1. ^ a b "Rudbeckia hirta". The Global Compositae Checklist (GCC) – via The Plant List.
  2. ^ "Rudbeckia hirta". County-level distribution map from the North American Plant Atlas (NAPA). Biota of North America Program (BONAP). 2014.
  3. ^ a b c Urbatsch, Lowell E.; Cox, Patricia B. (2006). "Rudbeckia hirta". In Flora of North America Editorial Committee (ed.). Flora of North America North of Mexico (FNA). 21. New York and Oxford – via, Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
  4. ^ Chen, Yousheng; Nicholas Hind, D. J. "Rudbeckia hirta". Flora of China. 20–21 – via, Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
  5. ^ Dolgopolov, Y. (2004). A collection of confusable phrases: False 'friends' and 'enemies' in idioms and collocations. Coral Springs, FL: Llumina Press.
  6. ^
  7. ^ Runkel, Sylvan T.; Roosa, Dean M. (1989). Wildflowers of the Tallgrass Prairie: The Upper Midwest. Ames, IA: Iowa State University Press.
  8. ^ a b "MARYLAND AT A GLANCE: STATE SYMBOLS, Maryland State Flower - Black-Eyed Susan", Maryland State Archives, Maryland Manual Online
  9. ^ a b c Moerman. D. (1998). Native American Ethnobotany. Timber Press. Oregon. ISBN 0-88192-453-9.
  10. ^ Floridata: Rudbeckia hirta.
  11. ^ RHS A-Z encyclopedia of garden plants. United Kingdom: Dorling Kindersley. 2008. p. 1136. ISBN 1405332964.
  12. ^ Andy's Northern Ontario Wildflowers: Native Meadow Wildflowers. Black-eyed Susan.
  13. ^ "RHS Plant Selector - Rudbeckia hirta 'Indian Summer'". Retrieved 2 June 2013.
  14. ^ "RHS Plant Selector - Rudbeckia hirta 'Toto'". Retrieved 2 June 2013.
  15. ^ "AGM Plants - Ornamental" (PDF). Royal Horticultural Society. July 2017. p. 93. Retrieved 11 October 2018.
  16. ^ Lacy, Allen (July 21, 1988). "Gloriosa, the Eliza Doolittle of Daisies". New York Times. Retrieved 2013-10-22.
  17. ^ "Fiscal and Policy Notes (HB 345)" (PDF). Department of Legislative Services - Maryland General Assembly. 2010. Archived from the original (PDF) on 2011-06-07. Retrieved 2010-03-13.
  18. ^ Reimer, Susan. "Neither Susans nor daisies", Baltimore Sun. May 16, 2014
  19. ^ The Drawl: The History and Traditions of the University of Southern Mississippi (PDF) (Centennial ed.). The University of Southern Mississippi. 2010. p. 10. Retrieved 5 September 2015.
  20. ^ Schillo, Rebecca (2011). Cummings, Nina (ed.). "Native Landscaping Takes Root in Chicago". In The Field: 13.
  21. ^ The Xerces Society (2016), Gardening for Butterflies: How You Can Attract and Protect Beautiful, Beneficial Insects, Timber Press.
  22. ^ Brandeis University, Black-Eyed Susan (Rudbeckia hirta)
  23. ^ Refdoc, Luczkiewz M., & Cisowski W. (2001). Optimisation of the second phase of a two phase growth system for anthocyanin accumulation in callus cultures of Rudbeckia hirta. Plant cell, tissue and organ culture 65: 57-68
  24. ^ "List of plants toxic to cats".

External links[edit]